From c93482a8b943a593608d8bae7156e357ed0002d5 Mon Sep 17 00:00:00 2001 From: Anton Hvornum Date: Thu, 26 May 2022 18:46:10 +0200 Subject: Rework btrfs handling (#1234) * Restructuring btrfs.py into lib/btrfs/*.py * Reworking how BTRFS subvolumes get represented, and worked with. Subvolumes are now their own entity which can be used to access it's information, parents or mount location. * Added BtrfsSubvolume.partition and other stuff. * Reworking the way luks2().unlock and .format() returns device instances. They should now return BTRFSSubvolume where appropriate. * Fixed a missing import * Fixed an issue where mkfs.btrfs wouldn't trigger due to busy disk. * Fixing subvol mounting without creating a fake instance. * Added creation of mountpint for btrfs subvolume * Fixed root detection * Re-worked mounting into a queue system using frozen mounting calls using lambda * Removed old mount_subvolume() function * Removed get_subvolumes_from_findmnt() * Fixed Partition().subvolumes iteration * Adding .root to BtrfsSubvolume * Fixed issue in SysCommandWorker where log output would break and crash execution due to cmd being a string vs list * Changed return-value from MapperDev.mountpoint to pathlib.Path --- archinstall/lib/disk/btrfs/btrfssubvolume.py | 191 +++++++++++++++++++++++++++ 1 file changed, 191 insertions(+) create mode 100644 archinstall/lib/disk/btrfs/btrfssubvolume.py (limited to 'archinstall/lib/disk/btrfs/btrfssubvolume.py') diff --git a/archinstall/lib/disk/btrfs/btrfssubvolume.py b/archinstall/lib/disk/btrfs/btrfssubvolume.py new file mode 100644 index 00000000..a96e2a94 --- /dev/null +++ b/archinstall/lib/disk/btrfs/btrfssubvolume.py @@ -0,0 +1,191 @@ +import pathlib +import datetime +import logging +import string +import random +import shutil +from dataclasses import dataclass +from typing import Optional, List# , TYPE_CHECKING +from functools import cached_property + +# if TYPE_CHECKING: +# from ..blockdevice import BlockDevice + +from ...exceptions import DiskError +from ...general import SysCommand +from ...output import log +from ...storage import storage + +@dataclass +class BtrfsSubvolume: + full_path :pathlib.Path + name :str + uuid :str + parent_uuid :str + creation_time :datetime.datetime + subvolume_id :int + generation :int + gen_at_creation :int + parent_id :int + top_level_id :int + send_transid :int + send_time :datetime.datetime + receive_transid :int + received_uuid :Optional[str] = None + flags :Optional[str] = None + receive_time :Optional[datetime.datetime] = None + snapshots :Optional[List] = None + + def __post_init__(self): + self.full_path = pathlib.Path(self.full_path) + + # Convert "-" entries to `None` + if self.parent_uuid == "-": + self.parent_uuid = None + if self.received_uuid == "-": + self.received_uuid = None + if self.flags == "-": + self.flags = None + if self.receive_time == "-": + self.receive_time = None + if self.snapshots == "": + self.snapshots = [] + + # Convert timestamps into datetime workable objects (and preserve timezone by using ISO formats) + self.creation_time = datetime.datetime.fromisoformat(self.convert_to_ISO_format(self.creation_time)) + self.send_time = datetime.datetime.fromisoformat(self.convert_to_ISO_format(self.send_time)) + if self.receive_time: + self.receive_time = datetime.datetime.fromisoformat(self.convert_to_ISO_format(self.receive_time)) + + @property + def parent_subvolume(self): + from .btrfs_helpers import find_parent_subvolume + + return find_parent_subvolume(self.full_path) + + @property + def root(self) -> bool: + from .btrfs_helpers import subvolume_info_from_path + + # TODO: Make this function traverse storage['MOUNT_POINT'] and find the first + # occurance of a mountpoint that is a btrfs volume instead of lazy assume / is a subvolume. + # It would also be nice if it could use findmnt(self.full_path) and traverse backwards + # finding the last occurance of a subvolume which 'self' belongs to. + if volume := subvolume_info_from_path(storage['MOUNT_POINT']): + return self.full_path == volume.full_path + + return False + + @cached_property + def partition(self): + from ..helpers import findmnt, get_parent_of_partition, all_blockdevices + from ..partition import Partition + from ..blockdevice import BlockDevice + from ..mapperdev import MapperDev + from .btrfspartition import BTRFSPartition + from .btrfs_helpers import subvolume_info_from_path + + try: + # If the subvolume is mounted, it's pretty trivial to lookup the partition (parent) device. + if filesystem := findmnt(self.full_path).get('filesystems', []): + if source := filesystem[0].get('source', None): + # Strip away subvolume definitions from findmnt + if '[' in source: + source = source[:source.find('[')] + + if filesystem[0].get('fstype', '') == 'btrfs': + return BTRFSPartition(source, BlockDevice(get_parent_of_partition(pathlib.Path(source)))) + elif filesystem[0].get('source', '').startswith('/dev/mapper'): + return MapperDev(source) + else: + return Partition(source, BlockDevice(get_parent_of_partition(pathlib.Path(source)))) + except DiskError: + # Subvolume has never been mounted, we have no reliable way of finding where it is. + # But we have the UUID of the partition, and can begin looking for it by mounting + # all blockdevices that we can reliably support.. This is taxing tho and won't cover all devices. + + log(f"Looking up {self}, this might take time.", fg="orange", level=logging.WARNING) + for blockdevice, instance in all_blockdevices(mappers=True, partitions=True, error=True).items(): + if type(instance) in (Partition, MapperDev): + we_mounted_it = False + detection_mountpoint = instance.mountpoint + if not detection_mountpoint: + if type(instance) == Partition and instance.encrypted: + # TODO: Perhaps support unlocking encrypted volumes? + # This will cause a lot of potential user interactions tho. + log(f"Ignoring {blockdevice} because it's encrypted.", fg="gray", level=logging.DEBUG) + continue + + detection_mountpoint = pathlib.Path(f"/tmp/{''.join([random.choice(string.ascii_letters) for x in range(20)])}") + detection_mountpoint.mkdir(parents=True, exist_ok=True) + + instance.mount(str(detection_mountpoint)) + we_mounted_it = True + + if (filesystem := findmnt(detection_mountpoint)) and (filesystem := filesystem.get('filesystems', [])): + if subvolume := subvolume_info_from_path(filesystem[0]['target']): + if subvolume.uuid == self.uuid: + # The top level subvolume matched of ourselves, + # which means the instance we're iterating has the subvol we're looking for. + log(f"Found the subvolume on device {instance}", level=logging.DEBUG, fg="gray") + return instance + + def iterate_children(struct): + for child in struct.get('children', []): + if '[' in child.get('source', ''): + yield subvolume_info_from_path(child['target']) + + for sub_child in iterate_children(child): + yield sub_child + + for child in iterate_children(filesystem[0]): + if child.uuid == self.uuid: + # We found a child within the instance that has the subvol we're looking for. + log(f"Found the subvolume on device {instance}", level=logging.DEBUG, fg="gray") + return instance + + if we_mounted_it: + instance.unmount() + shutil.rmtree(detection_mountpoint) + + @cached_property + def mount_options(self) -> Optional[List[str]]: + from ..helpers import findmnt + + if filesystem := findmnt(self.full_path).get('filesystems', []): + return filesystem[0].get('options').split(',') + + def convert_to_ISO_format(self, time_string): + time_string_almost_done = time_string.replace(' ', 'T', 1).replace(' ', '') + iso_string = f"{time_string_almost_done[:-2]}:{time_string_almost_done[-2:]}" + return iso_string + + def mount(self, mountpoint :pathlib.Path, options=None, include_previously_known_options=True): + from ..helpers import findmnt + + try: + if mnt_info := findmnt(pathlib.Path(mountpoint), traverse=False): + log(f"Unmounting {mountpoint} as it was already mounted using {mnt_info}") + SysCommand(f"umount {mountpoint}") + except DiskError: + # No previously mounted device at the mountpoint + pass + + if not options: + options = [] + + try: + if include_previously_known_options and (cached_options := self.mount_options): + options += cached_options + except DiskError: + pass + + if not any('subvol=' in x for x in options): + options += f'subvol={self.name}' + + SysCommand(f"mount {self.partition.path} {mountpoint} -o {','.join(options)}") + log(f"{self} has successfully been mounted to {mountpoint}", level=logging.INFO, fg="gray") + + def unmount(self, recurse :bool = True): + SysCommand(f"umount {'-R' if recurse else ''} {self.full_path}") + log(f"Successfully unmounted {self}", level=logging.INFO, fg="gray") \ No newline at end of file -- cgit v1.2.3-70-g09d2